Field: This invention relates to internal combustion engines which are designed to operate on gaseous hydrogen fuel. In particular, the invention relates to methods of inhibiting backfiring and reducing the generation of oxides of nitrogen during the operation of such engines.
State of the Art: Internal combustion engines utilizing hydrogen fuel may be operated at low power outputs without difficulty provided the timing is properly set for the gaseous hydrogen mixture used as the fuel. At higher power outputs, an intermittent problem of ignition in the intake manifold (backfiring) is encountered. Without some means of suppression of backfiring, the engine cannot be made to run continuously at the higher power outputs required in conventional automobiles. In addition, the formation of oxides of nitrogen (NO.sub.x) increases as the power output of an internal combustion engine operating on hydrogen fuel is increased.
In U.S. Pat. No. 3,983,882, issued to Roger E. Billings on Oct. 5, 1976, it is reported that the addition of water to the hydrogen-air mixture in the intake manifold of an internal combustion engine is an effective means of suppressing the tendency of the engine to backfire and of reducing the production of oxides of nitrogen during the combustion. In accordance with the teachings of that patent, gaseous hydrogen fuel is mixed with a predetermined amount of air, and water is added to the mixture of hydrogen and air at the intake manifold of the engine.